Interface instability within shear bands in nanoscale Au/Cu multilayers

Au/Cu multilayers with individual layer thickness ranging from submicron to nanometer scale were deformed by a nanoindenter. In the nanoscale multilayer, we found that the constituent layers were severely kinked within the indentation-induced shear bands. The layer interfaces inside the shear band gradually became unstable and even can no longer be observed after a critical, highly localized shear strain. A phenomenological model is proposed to understand the mechanism of the interface instability developed in the shear band.